So how many moons are there in the year? How many phases of the moon are there?

How many full Moons are there in a year?

There are 12 full moon names corresponding to the full Moon in each month, but sometimes there are more than 12 full moons in one year…

How many full Moons are there in a month?

Because our modern calendar isn’t quite in line with the Moon’s phases, sometimes we get more than one full moon in a month. This is sometimes known as a blue moon (see comment on month names, below.)

The eight phases of the Moon in order are:

  • new Moon
  • waxing crescent Moon
  • first quarter Moon
  • waxing gibbous Moon
  • full Moon
  • waning gibbous Moon
  • last quarter Moon
  • waning crescent Moon.

The full, quarter and new Moons are all the instants in time when the Moon is exactly fully, half or not at all illuminated from our perspective on Earth. The crescent and gibbous Moons each last approximately a week.

There are traditional names for each of the moons, depending on the local culture. Old almanacs in England used a series of poetic names to refer to each moon of the year. This began with the “Moon after Yule”, the name given to the first full moon after the winter solstice, and finished with the “Moon before Yule”, the last full moon before the following winter solstice. There are twelve full moons in most years, which means that three full moons occur during most seasons. One season in ten, however, contains four full moons; the third moon that occurs in such a season is called a “blue moon” (note that this is not the only definition of the term “blue moon” that is now in common use). Below is a table showing some of these from both England and North America. The North American Moon names differ slightly from tribe to tribe, but many assign either 12 or 13 full moons to the year. These names were then adopted by the Colonial Americans and have entered popular culture.

MonthEnglish NameNorth American Name
Moon After Yule
1st Full MoonWolf MoonJanuary: Wolf Moon
2nd Full MoonLenten MoonFebruary: Snow Moon
Spring Equinox
3rd Full MoonEgg MoonMarch: Worm Moon
4th Full MoonMilk MoonApril: Pink Moon
5th Full MoonFlower MoonMay: Flower Moon
Summer Solstice
6th Full MoonHay MoonJune: Strawberry Moon
7th Full MoonGrain MoonJuly: Buck Moon
8th Full MoonFruit MoonAugust: Sturgeon Moon
Autumn Equinox
9th Full MoonHarvest MoonSeptember: Full Corn Moon
10th Full MoonHunter’s MoonOctober: Hunter’s Moon
11th Full MoonMoon Before YuleNovember: Beaver Moon
December: Cold Moon

So, where’s that 13th Moon?

The idea that there are 13 moons in a year comes from the lunar calendar. The lunar cycle, or the time it takes for the moon to complete one full orbit around the Earth and go through all its phases, is approximately 29.5 days.

When you multiply 29.5 days by 12 months, you get 354 days, which is about 11 days shorter than the solar year of 365 days. Therefore, over the course of a solar year, there are typically 12 full moons, but because of the discrepancy between the lunar and solar cycles, about every two to three years, there is an extra full moon. This extra full moon is known as a “blue moon.”

To further complicate matters, there are different definitions for what a “blue moon” is. For simplicity, look it up here. They explain it very well, and their site has even more information such as when the next Blue Moon will be. They are also the source for the English Month names in the table above.

So, while most years have 12 full moons, some years will have 13 full moons, leading to the belief or statement that there are 13 moons in a year. This concept is often used in various cultures and traditions, including some forms of witchcraft and pagan practices, which may use the lunar calendar for rituals and celebrations.